2jz coils, which terminal is positive/negative?

[2jizzle]

am wiring microtech ltx12s up to motor, need to know which is which.

[Norbie]

Pretty sure the black-red wire is the positive.

[2jizzle]

posted same question on another forum also, have had two opposite answers!

Can any one make a definate call???

[Norbie]

Well I'm basing that on a wiring diagram of a US-spec 2JZ-GE (so single coil). I just found the 2JZ-GTE diagram and I can tell you the black-orange wire is the negative. So assuming the US-spec engine has the same wire colours, that's confirmed.

[chris davey]

each coil should have 2 wires and one wire will be the same colour on all of the coils. That wire is the positive one.

[pilot]

Are you wondering about the positive terminal on the primary side of a coil-pack? If yes, unless it has some kind of special item in it, it doesn´t matter which one you use as positive. A coil doesn´t have negative and positive terminals.

[chris davey]

I was told it didn’t matter for the injectors but it does for the coils? That was from 10secrx7 the microtech man.

[pilot]

I was told it didn’t matter for the injectors but it does for the coils? That was from 10secrx7 the microtech man.

It should be exactly the opposite. Incorrectly (inverted) connected injectors won´t open.

[chris davey]

I did them both correctly anyway

[1JZ-Rolla]

Injectors do not have polarity, they are just a basic coil type solenoid. Maybe there's some really fancy injector thats different, but i've not seen one.

Coils on the other hand do need to be wired with correct polarity, I'm not sure of the result if you don't, as i'm not prepared to try it

[Norbie]

If it's anything like the coils found in old cars with contact points, they'll still work if wired up backwards but not as good (ie weak spark).

[jonra23]

If it's anything like the coils found in old cars with contact points, they'll still work if wired up backwards but not as good (ie weak spark).

Exactly the same with electronic, it is to do with the way the field colapses around the secondary windings when the primary current stops flowing.

regards
jon

[pilot]

If it's anything like the coils found in old cars with contact points, they'll still work if wired up backwards but not as good (ie weak spark).

I meant "coils" in a general way. Those coils you mention (the device) have polarity because of their internal arrangement: primary and secondary have one end connected together and then to one of the external terminals.
Wasted spark coils, on the other hand, don´t have this problem (primary and secondary coils are totally isolated from each other).

Injectors DO have polarity. An injectors is an electro-valve. Wire it the opposite way and it will try to open to the wrong side and not let the fuel go out.

In a coil, when you change the way current moves around it, you are changing the direction of the magnetic field (principle of and electric motor). Anyone who has studied electricity to a medium level would know this.

[pilot]

Exactly the same with electronic, it is to do with the way the field colapses around the secondary windings when the primary current stops flowing.

regards
jon

No, it is to do with the fact that both coils (primary and secondary) are connected to receive positive polarity in the same terminal.

[jonra23]

No, it is to do with the fact that both coils (primary and secondary) are connected to receive positive polarity in the same terminal.

Sorry not true, couldnt be buggered finding a reference on the net to link, but will explain logic why not possible.

Secondary winding DOES NOT recieve any power supply, it converts the collapsing magnetic field from the primary windings back into electricity. In a simplistic method the amount of voltage generated by a coil is related to teh power supply voltage, number of primary windings and the number of secondary windings, (also related to saturation values and winding configuration).

Primary winding has constant 12 volt supply and is switched on earth by the ECU, Points, Igniter take your pick.
Secondary winding has one terminal to spark plug other terminal to ground, neither can be common with 12 volt supply, also neither can be common with switching earth or no swithching will happen.

regards
jon